Yard

By C Rae Hozer, Cumberland County Master Gardener

Typically gardeners like to buy supplies and plan outdoor tasks ahead of time. Folks often ask which things to purchase and when particular yard and garden tasks should be started. Many of the questions I’ve had so far this season start with the words “Is now a good time to…” or “When should I…”. Typically the question ends with a phrase like “fertilize my lawn”, “prune my crepe myrtle”, “apply crabgrass prevention”, or “use an insecticide to control scale”.

Timing is important for lots of lawn and garden activities but the best time to prune, fertilize, put down a pre-emergent herbicide to prevent crabgrass or to apply a treatment to control a particular insect pest can’t be defined by a specific calendar date. Instead, plan based on the season along with typical growth characteristics of the particular plant in question and/or on the life cycle of creatures and pathogens known to attack it. Plants, animals, insects, and plant disease pathogens also react to signals from the environment; air temperatures (highs, lows and averages), soil temperature, length of night, dry or wet conditions both above and below ground, the pH (acidity or alkalinity) of soil, etc. Work in light of those things along with the calendar.

In 2009, spring starts March 20 and the first day of summer is June 21. At some point between those two dates we’ll have our last frost. Tender plants won’t have a chance if placed outdoors too early without protection. Chain store retailers seem to stock flats of plants, garden ornaments, the latest lawn and garden equipment, bags of grass seed, lime, fertilizer, and cans of bug spray right after Christmas items are sold off. Buyer beware! Just because something is for sale in a store, doesn’t mean that day is the right time to plant or apply it. Early in March (a few years ago) while in line waiting to purchase some wildflower seeds and seed potatoes, I spotted a lady buying tomato plants. In the parking lot I asked if she had a greenhouse. She said “No. Why did you ask that?” I explained we don’t normally have our last frost in the Crossville area until about May 10. I didn’t know how she’d be able to keep those tomato plants alive for over two months without a greenhouse.

If you have a lawn of cool season turf like Kentucky bluegrass or fescue which you want to fertilize, to either over-seed or treat for crabgrass (but not both in one spring season), or if you need lime to bring the pH up (as indicated by a soil test) - buy the necessary supplies and/or equipment in late February or early March. March is good for work on existing cool season lawns. However, autumn is the best time to start a new lawn with this type of grass.

Crabgrass prevention stops weedy grass seeds from sprouting. The first application should be made just as soil reaches the right temperature for grass seed germination. Most of us don’t have a thermometer to gauge soil temperature, but Mother Nature gives us a good clue every spring. Apply your initial pre-emergent crabgrass treatment when the yellow flowers on Forsythia bushes are in full bloom. That is generally sometime in March or as late as April 1, if spring weather stays consistently cool.

Plateau Gardening is written by Master Gardeners for those tending home landscapes and gardens in Tennessee’s Upper Cumberland Region. Contact UT Extension Cumberland County, P.O. Box 483, Crossville, TN 38557, (phone 931-484-6743) for quick answers to specific questions, free publications, or to learnabout becoming a Master Gardener. Email comments or yard and garden inquiries to Master Gardener Rae, mgardenerrae@frontiernet.net.